Conditional knockout mice lacking K(ATP) channel subunits

描述（由申请人提供）：KATP 通道对于许多不同类型的细胞和组织的功能来说是不可或缺的。然而，尽管它们在大约 25 年前首次被描述，但这些通道对于大多数组织的生理和病理生理作用直到现在才显现出来。电生理学和药理学方法使我们能够更好地了解 KATP 通道的作用。 KATP 通道（Kir6.1、Kir6.2、SUR1、SUR2A 和/或 SUR2B 亚基）的分子鉴定进一步加深了我们对这些通道的分布和功能的了解。要检验的最重要的假设是，生理和病理生理事件受多个组织中存在的 KATP 通道活动的影响，并且不同组织类型中通道活动之间的同步相互作用决定了生理或病理生理结果的性质。传统的药理学方法不能用于在复杂的生物环境中检验这一假设，因为这些化合物缺乏对不同组织类型中存在的不同类别的 KATP 通道所需的特异性。已经为每个 KATP 通道亚基开发了传统的基因敲除小鼠模型，这些动物模型的可用性极大地增加了我们对 KATP 通道在体内环境中功能的了解。然而，由于所有体细胞中的表达都被消除，因此在复杂的生物环境（例如缺血/再灌注）中定义 KATP 通道亚基的作用时，这些动物的使用带来了挑战。为了检查多个组织中存在的 KATP 通道的相互作用以及它们在不同组织类型中的同步相互作用，需要新的工具，其中仅在特定组织、细胞类型或亚细胞区室中消除 KATP 通道。因此，本提案的目的是生成每种 KATP 通道亚基的条件敲除的四种小鼠模型。鉴于 KATP 通道的丰富多样性（无论是组织分布还是分子组成），迫切需要产生缺乏每个 KATP 通道亚基的条件敲除小鼠。这些动物模型的开发不仅会对我们自己的研究产生广泛的影响，而且还会对整个领域产生广泛的影响，因为作为这些研究的一部分产生的这些动物将使不同领域（心脏病学、内分泌学、神经学等）的研究人员能够揭示 KATP 通道在健康和疾病中的组织特异性功能。公共健康相关性：ATP 敏感 K 通道的独特之处在于，它们将细胞内能量代谢转化为细胞活动和兴奋性，对许多不同细胞类型的功能具有非常重要的作用，有助于维持血糖水平、调节血流、参与神经递质的分泌并防止缺血性损伤。在生理和病理生理背景下的 KATP 通道研究中出现了新的挑战，无法使用现有工具（即使使用现有的传统敲除小鼠）解决这些挑战，这就是我们建议生成新的基因改造小鼠模型的基本原理，在该模型中，可以在某些组织类型中特异性删除 KATP 通道亚基。这些将与科学界广泛分享的小鼠无疑将在许多研究领域（除了我们自己的研究之外）带来KATP通道研究的重大突破，这将对生物医学、行为和临床研究领域产生重大影响。

DESCRIPTION (provided by applicant): KATP channels are integral to the functions of many different types of cells and tissues. However, even though they were first described almost 25 years ago, the physiological and pathophysiological roles of these channels are only now emerging for most tissues. Electrophysiological and pharmacological methods have allowed for a good understanding of the roles of KATP channels. The molecular identification of KATP channels (Kir6.1, Kir6.2, SUR1, SUR2A and/or SUR2B subunits) has further advanced our knowledge regarding the distribution and function of these channels. The overriding hypothesis to be examined is that physiological and pathophysiological events are subject to the activity of KATP channels that are present in multiple tissues and that synchronous interaction between channel activities in diverse tissue types determines the nature of the physiological or pathophysiological outcome. Conventional pharmacological methods cannot be used to examine this hypothesis in a complex biological setting since these compounds lack required specificity for different classes of KATP channels present in diverse tissue types. Conventional knockout mouse models have been developed for each of the KATP channel subunits and the availability of these animal models has added significantly to our knowledge of the functions of KATP channels in the in-vivo setting. However, since the expression is eliminated in all somatic cells the use of these animals provides challenges when defining the roles of KATP channel subunits in complex biological settings (such as ischemia/reperfusion). To examine the interplay of KATP channels present in multiple tissues and their synchronous interaction in diverse tissue types, new tools are needed in which KATP channels are eliminated only in specific tissues, cell types or subcellular compartments. The purpose of this proposal is therefore to generate four mouse models of conditional knockouts of each of the KATP channel subunits. Given the rich diversity of KATP channels (both in terms to their tissue distribution and molecular composition), a dire need exists to generate conditional knockout mice devoid of each of the KATP channel subunits. The development of these animal models will have a wide ranging impact, not only on our own research, but also on the field in general since these animals generated as part of these studies will allow investigators working in diverse areas (cardiology, endocrinology, neurology, etc) to unravel the tissue specific functions of KATP channel in health and disease. PUBLIC HEALTH RELEVANCE: ATP-sensitive K+ channels are unique in that they transduce intracellular energy metabolism to cellular activity and excitability and they have very important roles on the functions of many different cell types and they help to maintain blood glucose levels, regulate blood flow, participate in the secretion of neurotransmitters and protect against ischemic insults. New challenges have arisen in the study of KATP channel in physiological and pathophysiological context that cannot be addressed using existing tools (even with the available conventional knockout mice), which is the rationale for our proposal to generate new genetically altered mouse models in which KATP channel subunits can be deleted specifically in certain tissue types. These mice, which will be widely shared with the scientific community, will undoubtedly lead to significant breakthroughs in the study of KATP channels in many study areas (in addition to our own research) and this will have a major impact on the fields of biomedical, behavioral and clinical research.